1. Field of the Invention
The present invention relates to an information processing apparatus, information processing method, and storage medium.
2. Description of the Related Art
A conventional technique arbitrates data to be swapped in data swapping when the internal memory is insufficient.
To ensure inseparable accesses for a plurality of access requests such as read modify write, one method issues a lock signal to a slave apparatus to permit an exclusive access.
To prevent access contention in data transfer between respective memories and a shared memory in a system including a plurality of data flow processors, a memory configuration capable of 2-port independent input and output and a communication packet format have been proposed (see Japanese Patent Publication No. 6-42266).
There is also proposed a method of storing dummy data in a read access request data area and sending it when a shift register transfer path is formed by series-connecting registers corresponding to a plurality of processing elements and data is transferred by the access request packet scheme (see Japanese Patent No. 4359490).
As an error check method, data transferred from a transmitting register to a receiving register is transferred again from the receiving register to the transmitting register. The previously transferred data held in the transmitting register is compared with the currently received data, efficiently checking an error (see Japanese Patent Publication No. 4-39929).
As for error diffusion process in image processing in a digital copying machine or the like, a streak generated at the boundary between divided scanning ranges is canceled by diffusing an error by overlapping of pixels by a larger number of lines than an actual binary output region (see Japanese Patent Laid-Open No. 63-309456).
For example, in the error diffusion process, it is important to retain an error from a surrounding pixel for higher image quality, as described in Japanese Patent Publication No. 4-39929. Save and recovery of error data are performed for a plurality of memory areas to implement the above image process with poor memory resources in a system which holds a plurality of parameter spaces separated or independent for respective colors. However, a conventional memory data swapping method cannot use a read area and write area for different application purposes. In addition, the system efficiency lowers owing to redundant data transfer caused by inputting dummy data in response to a read request, or waste of the memory band by frequent read and write requests.
To solve the above problems, the present invention provides a technique of improving data swapping performance.